Barnes and Noble has been quietly erasing all mentions of its Nook for PC and Mac, but now we have the first official confirmation that both are no more. An official statement, reported by The Digital Reader, says that the company is no longer supporting software for Windows 2000/XP/Vista or Mac OS X, and is directing users to switch to Nook for Web in its place. That, or you could always help prop up the company's brick-and-mortar operations by purchasing some of these.